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AJvYcCVvdi6w5lcUQCoqEDe0XEc9SmDNu6df8MtRvk70z7QEvFl0Kw81R0MF5jlw2Xeqso/y8HTk/HTww7tKeyo=@vger.kernel.org X-Gm-Message-State: AOJu0YxZx9PYvP1tPxdO+zBMI9JG0bGttdQTxZPhnWBM6wYvkUgZz9xd 1TeRnvMZjNKiLLV8IivqQYjH38YvqLxXSINQglDfK1SiD8eIwNuqNFqQQyRMiz/SPpQ+TOqsG+N WhjKhHtHT5NlnWxz0QjdN+A== X-Google-Smtp-Source: AGHT+IEoSfdY0P3iXQY3FCb+tHcmigvpocatUt6YkOF7zXtHSG/5g+bu26HCdo+YrjUqY1sE2DfDGCXrnlid7WmZ X-Received: from wmrc15.prod.google.com ([2002:a05:600c:acf:b0:476:ddb0:2391]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:1f85:b0:477:9c73:267f with SMTP id 5b1f17b1804b1-477c01ff629mr365899995e9.33.1764668208923; Tue, 02 Dec 2025 01:36:48 -0800 (PST) Date: Tue, 2 Dec 2025 09:36:11 +0000 In-Reply-To: <20251202093623.2337860-1-vdonnefort@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20251202093623.2337860-1-vdonnefort@google.com> X-Mailer: git-send-email 2.52.0.107.ga0afd4fd5b-goog Message-ID: <20251202093623.2337860-19-vdonnefort@google.com> Subject: [PATCH v9 18/30] tracing: Check for undefined symbols in simple_ring_buffer From: Vincent Donnefort To: rostedt@goodmis.org, mhiramat@kernel.org, mathieu.desnoyers@efficios.com, linux-trace-kernel@vger.kernel.org, maz@kernel.org, oliver.upton@linux.dev, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com Cc: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, jstultz@google.com, qperret@google.com, will@kernel.org, aneesh.kumar@kernel.org, kernel-team@android.com, linux-kernel@vger.kernel.org, Vincent Donnefort Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The simple_ring_buffer implementation must remain simple enough to be used by the pKVM hypervisor. Prevent the object build if unresolved symbols are found. Signed-off-by: Vincent Donnefort diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 53534447e70b..38523ea2e19b 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -114,4 +114,20 @@ obj-$(CONFIG_TRACE_REMOTE) +=3D trace_remote.o obj-$(CONFIG_SIMPLE_RING_BUFFER) +=3D simple_ring_buffer.o obj-$(CONFIG_TRACE_REMOTE_TEST) +=3D remote_test.o =20 +# +# simple_ring_buffer is used by the pKVM hypervisor which does not have ac= cess +# to all kernel symbols. Fail the build if forbidden symbols are found. +# +UNDEFINED_ALLOWLIST :=3D memset alt_cb_patch_nops __x86 __ubsan __asan __k= asan __gcov __aeabi_unwind +UNDEFINED_ALLOWLIST +=3D __stack_chk_fail stackleak_track_stack __ref_stac= k __sanitizer +UNDEFINED_ALLOWLIST :=3D $(addprefix -e , $(UNDEFINED_ALLOWLIST)) + +quiet_cmd_check_undefined =3D NM $< + cmd_check_undefined =3D test -z "`$(NM) -u $< | grep -v $(UNDEFINED_= ALLOWLIST)`" + +$(obj)/%.o.checked: $(obj)/%.o FORCE + $(call if_changed,check_undefined) + +always-$(CONFIG_SIMPLE_RING_BUFFER) +=3D simple_ring_buffer.o.checked + libftrace-y :=3D ftrace.o --=20 2.52.0.107.ga0afd4fd5b-goog